Jake Vossenkemper

This morning I am getting lots of questions about what impact yesterday’s cold rain had on corn stand establishment. The short answer is the cold rain likely had very little impact on seed viability or final stands. For a further explanation, I would like to point you to a very well done video explanation by our new DeKalb Technical Agronomist, Nicole Stecklein. She is very knowledgable in agronomy and I encourage you to get to know her after meetings and other co-sponsored Liqui-Grow/DeKalb events.

The 2019 growing season has been anything but “normal” thus far. We have had well above normal precipitation, below normal heat unit accumulation and delayed planting. Moreover, the extended 3 month forecast published by NOAA and the National Weather Service calls for higher than normal probabilities of precipitation and lower than normal temperature probabilities thorough out the remainder of the summer (figures 1 & 2).

Figure 1. NOAA 3 month precipitation outlook

Figure 2. NOAA 3 month temperature outlook.

These facts have resulted in many sales agronomist and growers wondering if the crop will make it to black layer (maturity) prior to a killing frost? To help answer these questions I have used a decision support weather model/tool developed by the Midwest Climate Center and their affiliates to help derive some insights into this question.

To help answer this question I plugged in 3 hypothetical planting dates (May 25th, June 5th and June 15th) into the U2U weather/GDD model, and three different maturities spanning early to full maturity corn hybrids. I also ran the U2U weather tool at 4 different latitudes. A latitude approximating Roseville, IL, Davenport, IA, Clear Lake/Hampton, IA and Elkhorn, WI. While I won’t take the time to carve through all the graphs and data, I will give a brief synopsis of my findings.

Fun fact, the definition of a killing frost is when temperatures reach 28 degrees F or colder. This temperature is usually cold enough to turn water within plant cells into ice crystals. These expanding ice crystals burst cells and are usually lethal to the entire plant. Hence “killing frost”.

Roseville, IL & Davenport, IA Latitudes

In general I found that hybrids ranging from 104 RM to 114 RM have a high probability of making it to black layer prior to a killing frost at the Roseville, IL and Davenport, IA latitudes (figure 3 & 4) when planted by May 25th or earlier planting dates. For hybrids planted on June 5th, it looks like the 104 to 110 day RM hybrids will also have a good chance of making it to black layer prior to a killing frost, but very full hybrids (113 to 114 RM) may experience a killing frost prior to black layer at these latitudes (figure 3 & 4). Any hybrid (104 to 114 RM) planted on or after June 15th at the Roseville, IL and Davenport, IA latitudes has a 50% chance or greater probability of experiencing a killing frost prior to black layer.

Clear Lake & Hampton, IA & Elkhorn, WI Latitude

For the latitude’s close to Elkhorn, WI any mid and short-season hybrids (95 to 101) planted on or before May 25th have a greater than 50% chance of making in to black layer prior to a killing frost, but full maturity hybrids (107) even when planted on May 25th have a poor chance of making it to black layer prior to a killing frost (figure 6). If corn was planted on June 5th only the short-season hybrids (95) hybrids have a good chance of making it to black layer before a killing frost at this latitude (figure 6). For regions close to this latitude all RM hybrids (95 to 107) planted on or after June 15th don’t seem to have a good chance of making it to black layer if we have a normal frost date (Oct 18th) for this region. But most full-season hybrids at this latitude are grown for silage, so a killing frost is likely not to be a concern for those silage acres given harvest is much sooner than when harvesting for grain.

Figure 5: The % chance of corn hybrids reaching black layer prior to a killing frost for 3 hypothetical planting dates at latitudes close to Clear Lake and Hampton, IA.

The Good News

While a killing frost sounds devastating to yield, a killing frost when grain yield is still rapidly accumulating during mid and early reproductive growth/development is rare. The more likely scenario is that we may experience a killing frost very late in the grain filling period (also known as reproductive growth period). A killing frost at 35 to 40% kernel moisture usually has negligible effects on grain yield, given all yield has nearly been accumulated. A rarer scenario is that we could experience a killing frost at half milk line, this could result in more severe yield losses, (10 to 15% range), slower field drying, difficulty shelling kernels from cobs and poor test weight. The best scenario for us all would be a warm dry fall.

How to Correct the Nitrogen Loss

Nitrogen loss will be a big concern in 2019 given all the wet weather. As such and for good reason, there have been many questions regarding how much N may have been lost and what we can do to go about correcting these N loss problems. To address these concerns and questions I have made a video discussing these various issues. As you will learn in this video I will produce a second video with PSNT soil test results and nitrogen model estimations of N loss which may refine my initial thoughts and recommendations. 2019 is off to a rough start, but the more in-the-know you are, the better your yield.

If you had more than 10 inches of rain since N was applied its advised that you recommend applying more. Nitrate soil tests are confirming this.

N models don’t seem to be aligning very well with the nitrate nitrogen tests that I took and some general knowledge about what we know regarding rain fall amounts and precipitation.

Bottom line, N models may be valuable, but they don’t replace good sound experience and agronomic advise. Follow recommendations from N models with caution.

Summary

Ortho-phosphates are 100% plant available, but a high percentage of poly-phosphates in starter fertilizers convert to ortho-phosphate within just two days after application.

This quick conversion from poly to ortho-phosphate suggests expensive “high” ortho starter fertilizers are not likely to result in increased corn yields compared to conventional poly-phosphate starters.

On-farm field studies conducted near Traer, IA and Walnut, IL from the 2016 to 2018 growing season found no statistical difference (Pr > 0.05) in corn yield between conventional and high ortho-phosphate starters.

High ortho starters cost more per/ac than conventional poly-phosphate starters, but do not increase corn grain yields.

Poly-phosphates Rapidly Convert to Plant available Ortho-Phosphates

Given poly-phosphates are not immediately plant available and ortho-phosphates are immediately plant available, this gives the promoters of “high” ortho-phosphate starters ample opportunity to muddy the waters. Nevertheless, the facts are, poly-phosphates are rather rapidly hydrolyzed (converted to) into ortho-phosphates once applied to soils, and this hydrolysis process generally takes just 48 hrs or so to complete.

In Sept of 2015 I posted a blog discussing some of the more technical reasons why the ratio of ortho- to poly-phosphates in starter fertilizers should have no impact on corn yields. For those that are interested in the more technical details, I encourage you to follow this link to
the Sept 2015 blog post (liqui-grow.com/farm-journal).

While we were relatively certain that the ratio of ortho to poly-phosphates in liquid starters should have no effect
on corn yields, I decide to “test” this idea with on-farm field trials located near Traer, IA and Walnut, IL in the 2016, 2017 and 2018 growing seasons.

Picture 1. Planting starter fertilizer trials near Traer, IA in the growing season of 2016.

How the Field Trial Was Conducted

In these field trials we used two starters applied in-furrow at 6 gal/ac. Each starter had a NPK nutrient analysis of 6-24-6. The only difference between these two starters was the ratio of ortho to poly-phosphates. One of these starters contained 80% ortho-phosphate and the other contained just 50% ortho-phosphate. With the remainder of the phosphorous source in each of these two starters being poly-phosphate. At the Traer, IA locations the plots were planted with a 24-row planter (picture 1) and were nearly 2400ft long. At the walnut, IL locations the research was conducted using small plot techniques, plot dimensions there were 10 ft wide by 30 ft long. At both Traer, IA and Walnut, IL in each of the 3 growing season the experimental design used was a simple randomized complete block with 4 or 5 replications.

Figure 1. Average corn yield from field trials comparing high ortho vs conventional poly-phosphate in-furrow seed safe starter fertilizers. Yields at each location/year are averaged over 4 or 5 replications.

Field Trial Results

Averaged over the 5 site-years there was only about 1.5 bu/ac yield difference separating the high ortho and conventional poly-phosphate starter (figure 1). Moreover, this small yield difference was not statistically significant (Pr > 0.05). In addition to finding no differences in grain yield between these two starters, the high ortho starter cost about $0.50 more per/gal (so $3/ac difference in price at a 6 gal/ac rate) than the lower ortho starters. So the more expensive high ortho starter clearly did not “pay” its way in our multi-location field trials (figure 2). Lastly, our observations in these studies agree with previously published university findings (Frazen and Gerwing. 1997).

Crop scientists with the USDA/ARS and the University of Illinois genetically modified the mechanisms of photosynthesis which increased plant biomass production by 47%. This may be the foundation towards dramatically increasing crop yields.

Can you imagine the entire population of the United States, Canada, Mexico, Brazil, the United Kingdom and France going hungry?

You don’t need to imagine. That is exactly what happens every day when an estimated 815 million people around the globe go hungry. In the short term, the problem is likely to get worse as the population grows, diets change and urban sprawl forces farmers to produce more food on less land. Recent reports suggest that by the time children born today reach their 30s, the planet must increase food production by at least 70 percent.

The INRS is a science based study of the various best practices framers can implement to reduce the loss of Nitrogen and Phosphorus in Iowa. Watch the video to learn what management practices are recommended for top yields and environmental stewardship.

The goal of the Iowa Nutrient Reduction Strategy is to reduce Nitrogen losses by 41% and Phosphorus losses by 29%. In turn, this will improve yield, soil health and water quality throughout the state of Iowa. Not only will this improve nutrient levels in Iowa’s waters but also in areas down stream, including the Gulf of Mexico.

Liqui-Grow is conducting extensive crop management research in the 2018 growing season in northwest, IL and eastern, IA. This year, we have implemented research at 5 different sites and am conducting 25 different experiments. These experiments include simple corn hybrid evaluations, testing new fertilizer formulations, and extensive studies looking at how bacterial inoculations may interact with various fertilization strategies to name a few. In this short educational video, I review observations we’ve made in a fertilizer placement study located in northwest, IL.

That is yet to be determined of course, but we do know that the biological and bio-fertilizers market is estimated to grow from a current market worth of $6.7 billion to $12.9 billion by the year 2022. What’s this mean if I am a farmer? A rapidly growing biological market aimed at the agricultural sector means farmers need to become educated about what biologicals and bio-fertilizers may and may not be able to offer them. Over the last 4 months or so I have been browsing the scientific literature educating myself about what we do and do not know about these bio-fertilizers. I have learned that due to advancements in genome sequencing it is now much easier, faster and cheaper to identify and isolate specific bacterial and fungal strains that do in-fact provide services that can improve plant growth and yield.

Some of the agronomically important services bio-fertilizers may be able to provide include: atmospheric nitrogen fixation for cereal crops (corn, wheat, etc..), bacteria that are able to convert non-plant available forms of soil nutrients into plant available forms (phosphorus and potassium solubilizing bacteria), bacteria that can compete with plant pathogenic fungi and other harmful bacteria, and specific strains of bacteria have been shown to produce plant growth regulators (Indole acetic acid and gibberellic acids) that can stimulate root growth and development. See the bulleted list below for more specific details about what bio-fertilizers have been shown to be able to achieve is science-based studies.

Bio-Fertilizers 2018 Field Testing

The unfortunate part is that many of these known benefits of bio-fertilizers have been tested more often under greenhouse vs. actual field conditions. That said, there is an increasing amount of evidence that these bio-fertilizers may, in fact, be able to increase corn and soybean yields in actual field environments, but our knowledge in actual field conditions is clearly more limited than what has been shown in greenhouse studies. On this note, Liqui-Grow has partnered with several biological companies that are leaders in the bio-fertilizer market. We will be testing their most promising bio-fertilizer products at several locations throughout eastern, IA and northwest, IL in the 2018 growing season. My main objective at Liqui-Grow is to identify and investigate (in-formal field research trials) new and innovative products and crop management practices that can make our customers and our company more profitable – partner with us to find out what we learn.

Phosphate mobilizing or phosphorus solubilizing bio-fertilizers/microorganisms (bacteria, fungi, mycorrhiza etc.) converts insoluble soil phosphate into soluble forms by secreting several organic acids and under optimum conditions, they can solubilize/mobilize about 30-55 lbs P2O5/ac due to which crop yield may increase by 10-20%.

Bio-fertilizers act as antagonists/competitors and suppress the incidence of soil-borne plant pathogens and thus, help in the bio-control of diseases.

Nitrogen-fixing, phosphate mobilizing and cellulolytic microorganisms in bio-fertilizer enhance the availability of plant nutrients in the soil and thus, sustain agricultural production and farming system.

Bio-fertilizers are a cheap, pollution free and renewable energy sources.

2017 New Research

Article Summary

Orthophosphates are 100% plant available, but a high percentage of polyphosphates in starter fertilizers convert to ortho-phosphate within just two days after application.

This quick conversion from poly to orthophosphate suggests expensive “high” ortho starter fertilizers are not likely to result in increased corn yields compared to conventional polyphosphate starters.

On-farm field studies conducted near Traer, IA in the 2016 and 2017 growing season found no statistical difference (Pr > 0.05) in corn yield between conventional and high orthophosphate starters in either year.

High ortho starters cost more per/ac than conventional polyphosphate starters but do not increase corn grain yields.

Polyphosphates Rapidly Convert to Plant available Orthophosphates

Given polyphosphates are not immediately plant available and orthophosphates are immediately plant available, this gives the promoters of “high” orthophosphate starters ample opportunity to muddy the waters. Nevertheless, the facts are, polyphosphates are rather rapidly hydrolyzed (converted to) into orthophosphates once applied to soils, and this hydrolysis process generally takes just 48 hours or so to complete.

In September of 2015, we posted a blog discussing some of the more technical reasons why the ratio of ortho to polyphosphates in starter fertilizers should have no impact on corn yields. For those that are interested in the more technical details, we encourage you to follow this link to the September 2015 blog post.

While we was relatively certain that the ratio of ortho to polyphosphates in liquid starters should have no effect on corn yields, we decided to “test” this idea with on-farm field trials located near Traer, IA in the 2016 and 2017 growing seasons.

How the Field Trial Was Conducted

In these field trials, we used two starters applied in-furrow at 6 gal/ac. Each starter had an NPK nutrient analysis of 6-24-6. The only difference between these two starters was the ratio of ortho to polyphosphates. One of these starters contained 80% orthophosphate and the other contained just 50% orthophosphate. With the remainder of the phosphorus source in each of these two starters being polyphosphate. Each plot was planted with a 24-row planter (Picture 1) and was nearly 2400 ft long. In both the 2016 and 2017 growing seasons the experimental design used was a randomized complete block with 4 or 5 replications.

Field Trial Results

Averaged over the side-by-side replications there was less than 1 bu/ac difference in corn grain yield between the high ortho and low ortho polyphosphate starters in both the 2016 and 2017 growing seasons. In addition to finding no differences in grain yield between these two starters, the high ortho starters generally cost about $1 more per/gal (so the $6/ac difference in price at a 6 gal/ac rate) than the low ortho starters. So the more expensive high ortho starter clearly did not “pay” its way in our multi-year field trials.

More Trials Planned for 2018

While our findings agree with other research-comparing ortho and polyphosphate starter fertilizers (Frazen and Gerwing. 1997), we want to be absolutely certain that our fertilizer offerings are the most economically viable products on the market. Therefore, we have decided to run this same field trial at one location in northern, IL in 2018, and at one location in central, IA in 2018. Stay tuned for those research results next fall.